There are no absolute best beans. Your combination of high summer temperature and humidity limit choices a lot. You don't state what you want them for, fresh eating, canning, roma type, intense flavor, etc. Look at Emerite as a really good flavored commercially available pole bean. Rattlesnake is an old variety with high heat tolerance. If you want a roma type, Musica is pretty good.

7a VA here. Rattlesnake.

I have planted a 10' row of blue lake stringless poll beans the last 3 years in my garden in southeast Kansas...zone 6b which should be comparable to yours. Talk about abundant! We've eaten and canned for all 3 years. Last year I canned 36 pints and 20 quarts just from that 10' section. They vine about 8 to 9 feet as a rule.